Shock absorber



Junglz, 1934.

J.- MILLER SHOCK ABSORBER n Filed Jari; 2o, 1'933 Patented June 1.2,1934,.,1 l

1,962,665 snoox `nsonnnn John L. Miller. Dayton, Ohio. j assignments,toy General Detroit, Mich.. l com .Application 20,

assigner, by mesne Motors Corporation, ration o! Delaware `193s, serialNo. '652,566

11min. (ci. iss-ss) This invention relatesl to improvements `inhydraulicshock absorbers. v L

It is among the objects of the present invention to provide an hydraulicshock absorber with valve mechanism which is vadapted automatically toadjust itself in accordancewith the nature of the roadway over which thevehicle is being operated. Adjusting this valve mechanism causes theshock absorber topro'- vide an increased resistance to relativemovements of the body and axles of the vehicle. thereby improving ridingqualities thereof,

A further object of the present invention is to provide a shockabsorberv with a duid flow" control device which isautomaticallyadjustable in response to accelerations in thevelocity o!the movement of the vehicle body to which said shock absorber isattached. l

A still further object of the present inven-` tion is to provide anhydraulic shock absorber capable of being automatically adjusted toincrease ts resistance in response to accelerations in the reboundmovement of the vehicle body to which the shock absorber is attached.

y Furter objects and advantagesxvof the present` invention will beapparent fromthe following description, reference being hadto the accomfpanying drawing in which s "prekrrediembodie ment of one form of 'thepresent'invention is clearly shown.

In the drawing:

Fig. 1 is a fragmentary side view of the vehicle chassis showing a shockabsorber equipped with the present invention applied thereto. The roadwheels have beenomitted in this view for the sake of clearness. y

Fig. 2 is a longitudinal sectional view taken through the shockabsorben-certain parts there of being shown in elevation.

Fig. 3 is an enlarged detail sectional view of the adjustable fluid flowcontrol device of the shock absorber, the device in this 'view beingshown in normal position.

Fig. 4 is a veiw similar to Fig. 3, with the fluid flow control deviceshown in the position in which uid flow is established.

Fig. 5 is a view similar to Figs. 3 and 4 showing the device, however,in the fluid ilow restricting position.

Referring to the drawing and particularly to Fig. 1, the frame of thevehicle is designated by the numeral 20, said frame being supported uponthe vehicle axle 21 by springs 22.

The shock absorber comprising a. casing 25 is attached to the frame 20in such a position that its' operating arm may v'the axle 21. The shockprovides a'iluid reservoir 'the portion of the cylinder be anchored to lvabsorber casing 25 2B and a cylinder 27, wall inside the casing havinga port 28l providing communication between the inner end ofthe reservoir26.

A rocker shaft 29 is o f the casing, one end .of this tending outsidecylinder and the journalied,` transversely rocker shaft exthe casing andhaving the shock absorber operating arm 30 provided thereon.

The `free end cured to one end, of said xnemberz which is vtheicllrming'member 33.V absorber ,casing 25, rocker,-A

end of s link link'vbeng swivelly `iilimbv within shock Shaft 29: hasthe of this arm- 30 is swivelly serocker lever 34 attached v'theretofsothat'said lever. will rotate with shaft body or axle movements.,v A lidthe open end of the casing said lid being provided with fluid leaks.

As shown in Fig.

29-in response to 351s attached to by lscrews 36, gasket to prevent 2,thefree end-of rocker lever 34 lies adjacent the openend of cylinder 27so as to be engaged by the head 1,40 of `pis-- ton\. 41 which isAreciprocably supportedV within lcylinder 27 and forms `4:2 therein.'I'he piston the compression chamber head 40.-has a passage 43 providingcommunication' between the com.-

pression chamber 42 and ow through the passage 43 in the reservoir 26.Fluid the piston head 40 is controlled by a valve mechanism comprisingan intakevalve 45, is yieldably urged the head portion of which Vupontheinterior surface of the piston head 40 surrounding the passage 43.

Valve 45 has a tubular body portion 46 which -slidably supports thetubular body portion 47 of the pressurerelease valve 48 The pressurerelease v'alvel 48 is urged into engagement withV the intake valve 45 bya spring between the intake valve 45 4 9 interposed and a retainingcollar 50 secured at the outer endof the tubular portion 47y of valve48. -A side opening 51 in the body portion 47 of valve 48 is normallyheld within' the contines of the tubular-portion 46 of valve 45,however, in response to duid pressure within the compression chamber 42,valve 48 is moved so .that the side opening 51 thereof is uncovered bythe intake valve 45y and a fluid ow islestablished yfrom chamber 42 toreservoir 26 through the side open sage 43. This ilow, however, the sideopening 51. A spring between the end wall of the i118` 51l and pas-- isrestricted by 55 is interposed casing 25 and a will vlikewise rotate endf cylinder ilow oi iiuid past an initial ilow of cage 56 which is urgedagainst the inner wall of piston head 40. This cage provides an abutmentfor one end oi a spring 57, the other end of this spring engaging intakevalve 45, urging said intake valve into engagement with the interiorsurface of the piston head so as to close passage 43.

The fluid flow control device Just described operates as follows: y l

In response to the road wheels of the vehicle striking an obstruction orraise in the roadbed, axle 21 is thrust upwardly toward the frame20,.compressing spring 22, thus the link 31 will move arm clockwise asregards Fig. 1 and consequently rocker shaft 29 and its arm 34clockwise. 'Ihis moves the free end of arm 34 away from the open end 'ofcylinderr27 and consequently spring 55 will cause piston 4,1'to m'oveoutwardlyfrom the cylinder 27 to follow this movement ofthe arm 34.Under-these circumstancesiluid from vthe reservoir, actingthroughpassage 43, will move intake valve from itsseat against the effect ofspring 57 toestablish fa substantially-free this valve 45 into thecompression chamber 42. Y

Upon the return oi.' the axle 21 to its normal position, which resultsin a separating movement between the frame 20 and axle 21,v arm 30 willbe rotated counter-clockwise and consequently arm 34 will ,be movedtoward the open 27, thereby moving the piston 41 within the cylindertoward its closed end. Pressure will now be exerted upon the iluidwithin chamber v43- which pressure, when attaining a proper degree, willact through the tubular portion 47 of the pressure release valve 48lagainst said pressure release valve and move it fromits seat on theintake valve 45 against the eiIect of the spring y49, therebyestablishing a restricted flow of iluid lthrough the ing 51 which. underthese conditions, will be moved without the coniines oi the intake valve45- i Fluid ilow control devices asdescribed heretofore'have been usedvin previous shock absorbers, however, the present provision of astatic-valve adaptedv to establish uid from the compression theestablishment of a. pressure release valve chamber 42 previous to iluidnow by the high 48. The invention also contemplates the pro' vision oi.'an automatic mechanism adapted to render the static-valve inoperativeand consequently eliminate the ow established thereby, in response topredetermined accelerations in the velocity of the movement of the shockabsorber bodily and particularly vertically in one direction only. Thisdirectionis preferably the reboundl movement o1' the vehicle body/ormore speciflcallythe upward movementof the vehicle body away from theaxle 21.

This novel automatic iiuid ilow control device comprises a screw plugadapted to be threadedlyv received by an aperture in the casing 25substantially in coaxial alignment with the port 28. A cylinder 61 isinterposed between the screw plug 60 and the cylinder wall in which port28 is provided, one end of this cylinder being press-tted into the plug60A whereby this end of the cylinder may be said to be closed. The otheror open end of the cylinderv60. fits snugly into the port 28, a rib 62acting as an side openinvention contemplates thev abutment which engagesthe annular edge surrounding port 28. As will be seen in Figs. 3, 4 and5, the interior of the cylinder 6l is of two different diameters, thelarger diameter portion being designated by the numeral 64, the smallerby the numeral 65a. The larger diameter portion is adjacent the closedend of cylinder 61, the smaller is at the open end of said cylinderwhich ilts into the port 28. In the annular wall of the larger diameterportion of the cylinder 61 there are provided a lplurality of openings65. These openings are comparatively smaller than the openings 66provided in the annular `wall of the smaller diameter cylindricalportion. Within the cylinder there is provided a slidable piston y valvehaving a central, through passage 70 extending from end to end, thispassage having a restricted throat portion 93. An annular head 73, thesloping surface of which is adapted toen'gage the annular, inner edge ofthat portion of., the cylinder 61 which extends into the port-28, thisvalve head 73 normally shutting', off iluid ilow between it and thecylinder 6l; The upper or inner portion 75 of the slide valve has acollar 76 press-fitted thereon which fits slidably within the cylinder61, this sleeve having an annular groove77 at its inner end providing anannular chamber withinthercylinder 61 in 110 which a spring 78 isprovided. One end of this spring engages the shoulder on the sleeve 7,6yformed by its annular groove 77, the other end of the spring engagesthe shoulder 79 formed by the two interior diameter portions of thecylinder 115 61. This spring normally, yieldably, urges the valve sothat its head portion 73 is maintained in engagement with the end of thecylinder 61 i'ltti'ng into the port 28. As will be seen in Figs.. 3, 4'and'5, a chamber 81 is formed at the closed 120 end of cylinder 61vbythe sliding lpiston valve 80, this chamber having openings 65 leadinginto it at all times.

Upon the cylinder 61 there is slidably supported a sleeve. valve 85, thelower end of which 125 I has spaced ilanges 86 providing a saddle forreceiving-the forkedl end 87 of the inertia mass control device. Thisforked end 87 is shown partially dotted in Fig. 2. In the inner surfaceof s aid sleevevalve there is annular groove 88, said groove being incommunicationv with the .outside of the sleeve valve 85 through openings89 in the wall of the sleeve valve 85. Normally groove 88 is not incommunication with the openings 65 in the cylinder 6l 135 as shown inFig. 3. Upon the sleeve valve 85 therev is secured a baille collar 90,inwardly extending annular flanges 91, and 191 thereof ilttlng tightlyuponv the sleeve valve 85 so as to secure it immovably thereon andforming an 140 annular chamber 92 about the sleeve valve 85 whichconstantly communicates with openings 89. A plurality of holes 193 inthe lower flange 191 of the collar 90 provides outlets for chamber 92.The annular chamber 92 and its smaller 145. outlets provided by thebaille collar 90 about sleeve valve 85 tends to reduce Whistling andhissing noisesv usually caused by the ejection of iluid under pressurefrom a small opening, inasmuch as chamber 92 acts as an expansion cham-150 provided an ber for the fluid being ejected under pressure fromopening 89, opening 193 provides an exit for the fluid fromsaid chamber92. Any suitable restriction designated by the numeral 93 maybe providedin the passage 70, this restriction varying of course in accordance withthe degree of control desired. y

This portion of the invention acts in the following manner:

In response to the rebounding or expanding movement of springs 22,which, as has. been mentioned heretofore, results inV the downwardthrust of spring 22 relative tojthe lframe 20, piston 41 will be movedinwardly within the cylinder 27- to exert a pressure .upon the'fluidwithin the chamber 42. This fluidpressure is transmitted against thevalve head 73, assisting spring 78 in urging it againstr the lower endof theA cylinder 61. The fluid pressure is also directed through thepassage into vthe chamber 81 and, due to the fact that the area of thepiston-valve which forms one wallof this chamber is greater than thearea `of fthe valve. head portion 73', valve 80 will be` moved -by thediffer.- ential fluid pressure against the`.efi`ect of spring 78 andagainst the eliect of the--fluid' pressure acting on the valve 73, intothe position in which it is shown in Fig. `4, thus movinggthe valvevhead portion`73 out of engagement with: the end of the cylinder 61,thereby establishing a.fluid`. flow from port 28 into the annular'chamber 72 from where it may exit through passages into the reservoir26. If the orice95, presented by the moving of valve head 73 fromcylinder 61, is not suiicient properly to relieve the pressure4` inchamber 42, then valve 48 willbe moved fromY ,y

its seat to establish another flow .through "the piston passages 43 intothe reservoir. This iluid ilow control as just described willobtainVaslong asv the sleeve valve isl maintained in its normal position by theinertia control mass 100, which will now be described.

Weight 100 has a bracket 101 secured thereto which is pivoted on a pin102 carriedy in the casing 25. A-forked extension 87 of bracket 101 fitsinto the saddle provided by flanges 86 on `the slide valve 85 wherebysaid valve operatively connected to the inertia weight orcontrol"xr'iass.v A spring 103 interposed between an adjustmendscrew 104on the weight and the Wall. of cylinder 27 maintains the weight inproper balanced position whereby the sleeve valve 85 is held in normalposition in which it maintains openings 65 completely closed, thusmaking chamber 81 a completely closed chamber in which uid pressure maybe established to move the pistonvalve 80 to fluid flow 'establishingposition as described with regards to Fig. 4.

. Compression movement of the spring 22 will tend to urge the vehiclebody carrying frame 20 upwardly. When the springs have reached the limitof their compression caused by the respec-A tive obstruction being met,they will vreturn to normal load position. However the vehicle, due toitsv inertia and, having been started upwardly, willftend to continue onits upward movement. .If this upward movement of the frame whichlsupports the body is substantially of constant velocity, weight member100 will not l become effective to adjust the fluid flow control deviceof the shock absorber. Howeven,l if the velocity of the rebound movementofthe vehicle frame upwardly isA sumciently accelerated, weight 100 willmove relatively to the shock absorber casing 25 due to its inertia andthus a is in the position shown in Fig. 5.

downward thrust of the weight, will cause an upward movement of itsforked end bracket 87, resulting' in an upward movement of the sleevevalve 85 whereby its interior annular groove' 88 is aligned withopenings 65 in the cylinder 61 as shown in the Fig. 5. This permitspressure in chamber 81 to be exhausted through the openings 65, groove88 and openings 89 in the sleeve valve 85 and consequently the pressureeffect upon the inner, larger end of the pistonvalve is substantiallyeliminated. Now the fluid pressure upon the valve head portion 73becomes predominant and the valve 80 is quickly moved into engagementwith the inner end of ythe cylinder 61 whereby the fluid flow betweensaid valve head 73 4and the cylinder is entirely cut, olf. Thisnaturally eliminates the static valve and thus substantially all fluidflow must obtain through thepressure release valve 48.

' It is of course understood that a slight tlow will always occurthrough the central passage 70 of valve 80 through chamber 81, sideopenings 65, groove 88 and openings 89 as long asthe valve However,restriction 93 in passage 70 is so great and openings 65 and 89 in thecylinder and sleeve valve respectively are so small that the volume ofliuid ilow therethroughA is substantially negligible; thereforeapplicant has said that practically all the 'fluid flow Iromthe chamber42 when -valve 73 engages cylinder. 61 must take place through theAcheck. valve 48.

It will of course be understood that as soon as the accelerations in carbody movements upwardly have reached a constant velocity, weight 100will again be returndtoits normal position by spring 103` so'that valves48 and 80 may act in conjunction to provide proper control of the shockabsorber resistance.v

From the aforegoing it may be seen that applicant has provided a simpleand compact hydraulic shock absorber,y capable of being automaticallyadjusted to vary .its resistance in accordance with the nature of theroad over which the vehicle is being operated. If the road is rough andextensive car body movements result, the shock absorber'is adjusted toprovide greater resistance to rebound movement -of the vehicle body,while on lthe other hand if the vehicle is being operated over acomparativew smooth highway orboulevard, the shock absorber vresistanceis substantially reduced due to the fact that the weight 100 will remainin its normal position in which the low 4pressure static valve 73 mayfunction.-

While the form of embodiment of the'present invention as hereindisclosed, constitutes a pre-A lferreddorm, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

What is claimedis as follows:

1; An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet` port; a check valve normally closing said portbut adapted, in response to a predetermined uid pressure, to open saidport; andan inertia mass controlled valve adapted to begopor normalpositions;

- stantially to close ferential areas upon which fluid pressure may actto move the valve either to port opening and an inertia mass controlledvalve normally rendering said check valve effective to fluid pressure toopen the port and adapted to be moved out of normal position in responseto accelerations in the velocity of vertical movement of the shockabsorber bodily to render said check valveeffective to fluid pressuresubstantially to close the port.

' 3. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; a check-valve normally closing said port,said valve having portions of differential areas both of which fluidpressure may act to provide a differential effect to move the valve intop'ort opening position and only upon one of said portions to move thevalve into complete port closing position; and an inertia masscontrolled valve adapted to be moved in response to accelerations in thevelocity of shock absorber movements bodily in one direction to causefluid pressure to be exerted on one portion only of said check-valve.

4. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; a check-valve yieldably urgedsubstantially to close the port and adapted to bemoved by uid pressureeither to open the port or substantially to -lclose the port; and aninertia mass controlled valve adapted, when, normally closed to rendersaid check-valvesusceptible to being opened by fluid pressure, and whensaid inertia valve is opened,'said check-valve is rendered susceptibleto being closed substantially by fluid pressure.

5.,An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; a check-valve yieldably urgedsubstantially to close the port and adapted to be moved by fluidpressure either to open the port or subthe port; a normally closedcontrol-valve adapted to render said checkvalve susceptible to beingopened by fluid pressure; and an inertia mass connected to thecontrol-valve and adapted to move it into open position in response toaccelerations in the velocity of casing movements in one direction only,for rendering the check-valve susceptible to being moved intosubstantial port closing positionby fluid pressure.

6. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; a differential valve yieldably urged,normally to close said port and adapted to have uid pressure exertedupon its opposite ends of different areas for moving the valve to openthe port; and an inertia mass controlled valve adapted to be operatedinresponse to accelerations in the velocity of the shock absorbermovement bodily for rendering the pressure upon one end of thedifferential valve ineffective to effect the closing of said valve bypressure.

7. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; a check-valve yieldably urgedsubstantially to close the port, said check-valve having a ductextending from end to end thereof, vthe ends of thevalve differing inareas, the smaller end normally substantially closing the port; acontrol valve normally forming a closed charnber at the larger area endof the check-valve for moving said valve to open the port in response tofluid pressure from the displacement charnber; and an inertia massconnected to the control-valve for moving it to open the closed chamberand thus render the pressure upon the smaller area end of the valveeffective to move said valve substantially to close the port in responseto accelerations in the movement of the shock absorber bodily in onedirection.

8. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; a cylinder having one end tting into saidport, the' other end being closed,vsaid cylinder having openings in itsannular wall, a piston valve slidable Within said cylinder, one end of.said piston valve normally closing the end of the cylinder, but movableby fluid pressure upon the opposite end of the valve to establish a flowof fluid from the port through certain openings in the cylinder, saidpiston valve having a through passage connecting the port with thechamber formed at the closed end of the cylinder by the piston valve; acontrol valve normally closing the openings in the cylinder leading intothe chamber at its closed end, but adapted to be moved to open saidchamber to cause fluid pressure to operate the piston' valve toterminate the fluid flow from the port; and an 100 inertia massconnected to the control-Valve for moving it to uncover the openings'inthe cylinder in response to accelerations in the vertical movements ofthe shock absorber bodily in one direction only.

9. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet; a fluid flow control device normallyrestricting the flow of fluid through said outlet, but adapted to, beactuated by fluid pressure to decrease its 110 restriction to fluidflow; and an inertia mass controlled device adapted to render saiddevice ineffective to be actuated out of normal position by fluidpressure.

10. An hydraulic shock absorber having a fluid 115 displacement chamberprovided with an outlet passage; a valve normally closing said passage,but adapted to be actuated by Liuid pressure to open said passage; andan inertia mass controlled device for rendering the fluid pressureineffective to actuate the valve to open said passage, but rendering iteffective to actuate the f Valve to close said passage.

11. An hydraulic shock absorber having a fluidV displacement chamberprovided with an outlet; fluid flow control means yieldably urgednormally to restrict the flow of fluid through said outlet; a fluidchamber adapted to receive fluid from the displacement chamber forbuilding up a fluid pressure therein to move the said control means intoa lesser fluid flow restricting position; and an inertia mass controlleddevice adapted to open said fluid chamber to release the fluid pressuretherein in response to accelerations in the upward movement of the shock135 absorber.

12. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet;

vprevent fluid pressure build-up therein inv response to accelerationsin the upward movement of the shock absorber.

13. An hydraulic shock absorber having a fluid 35 displacement chamberprovided with an outlet port; a fluid flow control device normallyrestricting the flow of fluid through said port, but adapted to beactuated out of normal position by fluid pressure to decrease itsrestriction to fluid flow; means adapted to be actuated out of normalposition to render the fluid pressure effective only to urge the saiddevice into normal position; and an inertia control mass connected tosaid means and adapted to actuate it out of normal position in responseto accelerations in the movement of the shock absorber vertically.

14. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; a fluid flow control device having a valvenormally closing the port, but adapted to be actuated by fluid pressureto open the port and also to close the port; a member normally renderingthe fluid pressure effective to actuate the valve to open the port, butadapted to be actuated to render the fluid pressure effective to actuatethe valve to close the port; and an inertia control mass connected withthe said member for moving it out of normal position in,

response to accelerations in the movement of the shock absorbervertically.

15. An hydraulic shock absorber having a fluid displacement chamberprovided with an outlet port; pressure actuated means for controllingthe flow of fluid through said port; a valve for controlling the fluidflow to provide fluid pressure to actuate said means, either to increaseor decrease the restriction to fluid flow through said port; and aninertia control mass for actuating said valve to provide fluid pressurefor actuating the said means to increase restriction to uid flow throughsaid port in response to accelerations in the movement of the shockabsorber vertically.

16. An hydraulic shock absorber comprising, in combination, a casingproviding a uid reservoir and a cylinder; a piston in said cylinderforming a fluid displacement chamber therein; a tubular member havingopenings providing communication between the displacement cham'- ber andreservoir; a control valve in said tubular member normally shutting offcommunication between the chamber and reservoir through certain of theopenings in the tubular member and having provisions for maintainingconstant communication between said chamber and the other openings inthe tubular member; a valve normally closing said other openings in thetubular member; and an inertia control mass connected with said lastmentioned valve and adapted to actuate it to open said other openings inthe tubularmember in response to accelerations in the movement of thecasing vertically.

17. An hydraulic shock absorber comprising, in combination, a casingproviding a Huid reservoir and a cylinder; a piston in said cylinderforming a fluid displacement chamber therein;` a tubular member havingopenings adjacent opposite ends thereof, said openings being larger atone end than at the other end of said member, providing communicationbetween the displacement chamber and the reservoir; a plunger 100 valvein said tubular member, said valve having a longitudinal passageproviding constant communication between the displacement chamber andthe smaller openings in the tubularvmember; a spring normally urging theplunger valve 105 to shut off the said chamber from the larger openingsin the tubular member; a valve on the tubular member normally closingthe smaller openings therein; and an inertia control mass for actuatingsaid valve to open the smaller 110 'openings in the tubular member andcomplete communication therethrough between the displacement chamber andreservoir in response to accelerations in the upward movement of thecasing.

